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<h3><a name="SECTION0016313000000000000000"></a><a name="optparse-what-positional-arguments-for"></a>
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14.3.1.3 What are positional arguments for?
</h3>

<p>
Positional arguments are for those pieces of information that your
program absolutely, positively requires to run.

<p>
A good user interface should have as few absolute requirements as
possible.  If your program requires 17 distinct pieces of information in
order to run successfully, it doesn't much matter <em>how</em> you get that
information from the user--most people will give up and walk away
before they successfully run the program.  This applies whether the user
interface is a command-line, a configuration file, or a GUI: if you make
that many demands on your users, most of them will simply give up.

<p>
In short, try to minimize the amount of information that users are
absolutely required to supply--use sensible defaults whenever
possible.  Of course, you also want to make your programs reasonably
flexible.  That's what options are for.  Again, it doesn't matter if
they are entries in a config file, widgets in the ``Preferences'' dialog
of a GUI, or command-line options--the more options you implement, the
more flexible your program is, and the more complicated its
implementation becomes.  Too much flexibility has drawbacks as well, of
course; too many options can overwhelm users and make your code much
harder to maintain.

<p>

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<span class="release-info">Release 2.5.1, documentation updated on 18th April, 2007.</span>
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